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Re: Is clustering factor stored in pg_stats.correlation?

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AlexK987 <alex.cue.987@xxxxxxxxx> writes:
> I believe that tables' clustering factors are stored in pg_stats.correlation.

Dunno what you mean by "clustering factor", but pg_stats.correlation
stores the correlation coefficient between the sequence of the column's
data values and the sequence of their physical order.  Correlation
coefficient is defined in the usual way:
http://en.wikipedia.org/wiki/Pearson_product-moment_correlation_coefficient
so it ranges between +1 in your example (perfect ordering) and -1
(perfect descending order).

			regards, tom lane


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